Refrigerated self-service display case



Nov. 7, 1950 D. J. GREILING REFRIGERATED SELF-SERVICE DISPLAY CASE 4 Sheets-Sheet 1 Filed Sept. 24, 1948 1N VEN TOR. .UA1/fp J. EREIL ING BY @af/11' 9W Agzys.

Nov. 7, 1950 D. J. GRElLlNG REFRIGERATED SELF-SERVICE DISPLAY CASE Filed Sept. 24, 1948 4 Sheets-Sheet 2 IN VEN TOR.

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Patented Nov 7.',l 1950 REFRIGERATED SELF-SERVICE DISPLAY CASE David J. Greiling, Kendallville, Ind., assignor to McCray Refrigerator Company, Kendallville, Ind., a corporation of Indiana Application September 24,/1948, Serial No. 50,912 Claims. (Cl. (i2-89.5)

This invention relates to refrigerated selfservice display cases of the multiple shelf-type, and particularly to one having an upper and lower open-top display compartment and embodying a construction in which air within the case is cooled and circulated to both compartments.

Several types of display cases of this character have heretofore been used in'which the air is cooled by gravity circulation. Cases of this type, however, are` not always satisfactory due to limitations in the amount of cooling from a gravity coil and to increased refrigeration losses inthe open-top case as compared with a closed case.

An object of the invention is to overcome these weaknesses by the provision of a positive air circulation together with means foi` distributing air substantially even throughout the upper and lower refrigerated zones and maintaining 'substantially uniform temperature conditions under widely varying ambient conditions in said zone.

Another object of the invention is the provision of means for insuring uniform distribution and control of air used in cooling the several zones.

Further objects and advantages of the invention will be apparent from the following detailed description, and from the accompanying drawings, in which- Fig. 1 is a front perspective view of a case embodying the invention; Fig. 2 is a vertical section on the line 2-2 in Fig. 1; Fig. 3 is a central vertical section on substantially the line 3-3 in each of Figs. 4 and 5, with parts in full; Fig. 4 is a horizontal section on the line 4-4 in Fig. 2; Fig. 5 is a vertical longitudinal section on the line il-5 in Fig. 3, with parts removed, and Figs. 6 and 7 are horizontal sections, respectively, on the lines 6-6 and I-'I in Fig. 2, with parts broken away.

The case embodying the invention comprises a body I having a shallow front wall 2, a considerabhr higher rear wall 3, a bottom 4 and opposing end walls 5, 5, of any suitable heat insulating material and construction. The rear wall 3 is provided at its upper end with a forwardly extending canopy 6, in the present instance, inclining upwardly from such wall. Each end wall 5 is substantially the -height of the front wall 2 for a distance rearward therefrom, which, in the present instance, is more than half the length of the end wall, and then rises or is provided with an upright extension 'I which is joined at its top edge to the respective end of the top canopy 6 and has its rear vertical edge in close connection with the adjacent end edge of the rear wall 3.

The end space of the case above each end wall 5, in front of and to the top of each end extension 'I, is closed by an end member 8, preferably of glass so that produce within the case may be viewed therethrough. The rear edge .of this member joins with the front edge of the end extension 1 while its front edge is vertically disposed for a distance and then extends upwardly and rearwardly, in the present instance in a curved line, to the front edge of the canopy 6. The front wall is provided on its top with an upward extension 9, preferably of transparent material such as glass, which joins at its ends with the front vertical edge portions of the end members 8 through the medium of corner posts I0, or in any other suitable manner. The exposed interiorn and exterior surfaces of the walls 2, 3, 5, extensions 6 and "I, and at leastl the top of the bottom 4, are preferably faced with enameled sheet metal, as is customary in the construction of cases of this type.

The base portion of the case at the rear of the front wall 2 includes a built-in structure II forming a forwardly and rearwardly extending horizontal air conduit I 2 at each end of the base, a wide central forwardly and rearwardly extending air conduit I3 between said end conduit, and a cross air conduit I4 between said end conduits at their front ends and at the front end of said center conduit, as best shown in Fig. 4. The` conduit I4 communicates with the front end of the conduit I3 through an opening in which an electrically driven fan I5 is disposed to set up a forced circulation of air from conduit I4 to and through conduit I3. 'Ihe rear portion of conduit I3 is vertically restricted relative to its front portion and to the conduits I2 and I4, as shown in Fig. 3, and in this restricted portion,

, designated I3, are disposed the coils I6 of a refrigerating unit, such coils being mounted at their end portions in the side Walls of the conduit. The tube connections I1 between the coils and a refrigerant supply or generating source are located partially in one of the end conduits I2, as shown in Fig. 4.

Each end conduit I2 connects at its rear end with a respective down or return flue 20 (Figs. 2, 5 and '7) disposed in the respective rear corners of the case. This flue extends upward for a predetermined distance at one cross-sectional size and then continues upward a further distance at a reduced cross-sectional size, as shown in Fig. 2. The front wall of each flue 2G is designated 2I in Figs. 2, 6 and 7. Thelarge portion of the ilue 20 has communication at its top with the lower produce compartment A of the case through a screened opening 22 that is exposed both at its front and inner sides to said compartment. Expanded metal is preferably used for the screening of this opening. The upper restricted portion of the opening has communication through a similar screened opening 23 to the upper produce display compartment B of the case.

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The conduit I3, I3a, at its rear end, opens [nto a broad flue 25 in the lower rear horizontal corner portion of the case between the two down or corner flues 20. This iiue 25 has communication with the compartment A through its bottom, as hereinafter described. Above such point of communication, the nue 25 is restricted in a horizontal forward and rearward direction to form the ue part 26, which corresponds in width to the flue 25 and has its upper end in communication with the lower portion of the compartment B, as hereinafter described. The front wall of the iiue 26 is designated 21. The product compartments A and B are separated by a shelf 30 forming the bottom and front of compartment B. This shelf is disposed with its lower portion substantially on a level with the top of the front wall 9 of the compartment A and terminates at its front end inwardly a distance from said wall so as to provide an open top space for the introducing of product into and taking it from said compartment.

The shelf 30 comprises, in the present instance, a bracket arm 3| projecting forward from the front dge of each end extension 1, at the inner side of the respective end plate 8. This bracket a'rm includes an outer plate 3| that removably projects from the upright 1 at the outer side of the glass plate 8 and is held to the plate and bracket arm by a screw 3|b that extends through an opening in the plate and threads into a part of the shelf 30. A beam 32 connects the arms 3| at their front ends and supports the front end of an imperforate bottom apron 33, which is preferably stepped at its forward end portion and slightly declines rearwardly therefrom toward'the flue wall 21 to which it is attached, as shown in Fig. 3. A perforated bottom wall or partition 34 is disposed over the shelf bottom 33 to form a space 35 therebetween, and, in the present instance, is substantially horizontally disposed with its front end resting on the bottom 33 at or adjacent to the beam 32 and with its rear end resting on a support or bracket 36 on the ue wall 21. A top perforated shelf rack 31 is mounted above the partition 34 to form a space 38 therebetween and is supported on suitable brackets or supports 39 in the lower portion of the compartment B. The rack 31 is preferably in the form of a plurality of removable bottom pans or plates, as shown in Fig. 6, for supporting the product and having their bottoms perforated to permit the passage of cooled air therethrough into the supported product. The screen or partition 34 has larger openings than those in the rack 31, so as to offer less resistance to the passage of air therethrough than is oiered bythe portion 31. For this purpose the screen 34 is preferably expanded metal and the portion 31 is perforated sheet metal. Cooled air is admitted to the space 35 from the up flue 26 through a long opening 39 in the 'ue wall 21. It is found in practice that a better control and uniform `distribution of air to the compartment B is obtained by providing a second screen 40 throughout the length of the space 35 near its entrance.

The space 38, in addition to opening into the compartment B through the perforations in the shelf rack 31, also has its front and rear ends open thereto through passages 4I and 42, respectively, so that should merchandise be piled solidly over the perforations'a certain amount of air will still be discharged into the refrigerated zone above the shelf.

The front of the refrigerating compartment or zoneB is deiined by a forwardly and upwardly inclined wall 43 preferably of glass, and thisis held at its ends by arms 44 projecting upwardly and forwardly from the forward ends of the bracket arms 3|.

The main or imperforate bottom of the compartment A is formed, in the present instance, by the top of the bottom structure II, and above this are two,spaced superimposed perforated bottom parts 45 and 46 with the latter constituting the product supporting rack within the compartment. The part 45 is disposed over the rear vertically reduced portion of the structure I I to form the air chamber 41, the rear end of which is open to the rear air passage 25 through an opening 48 in the front wall thereof (Figs. 3 and 5). A screen 49 extends across the chamber 41 in forwardly spaced relation to the opening 48 and tends to diffuse and control the amount of air admitted to the chamber. The air passes from the chamber 41 into the space or chamber 56 beneath the rack 46, and then passes therefrom into the merchandise compartment A through the perforations in the rack 46 and also through passages 5| and 52 at the front and rear of said parts. The screen part 45, which may be expanded metal, has much coarser openings than those in the rack 46, so that the principal expansion or diffusion and wide distribution of the cooled air takes place in the chamber 50.

The member 45, in the present instance, is mounted at its forward edge on the top wall of the conduit I3, and at its rear on the front wall of the rear air outlet passage 25 above the opening 48. The bottom rack 46, which may comprise a plurality of perforated plates, may be supported on front and rear brackets 53.

Depending from the front edge of the canopy 6 and projecting down into the refrigerating zone B to a level preferably lower than the top edge of the front wall 43 of the shelf 30 is a downwardly and rearwardly projectingbaiiie 55 preferably with a mirror 56 on its front for the purpose well understood in the art. An electric heating element 51 is preferably provided in the lower portion of the baille to raise the temperature of the mirror sufficiently to prevent fogging due to its exposure to the refrigerated zone of the compartment B. No claim is 'made for this feature.

In the use of the case, air is circulated through the conduits I2, I2 and I3, I3B, in the base portion of the case by a fan I4, and such circulating air is cooled by a refrigerating unit comprising coils I6 in the conduit portion |35. The cooled lair discharges from this portion of the conduit into a rather large conduit portion 25 which is coextensive in length with the space between the corner down iiues 20, and from this conduit a portion of the cooled air enters through an opening 48 into the air distributing chamber 41 at the bottom of the refrigerating compartment A. The air in this compartment is batlied and substantially uniformly dispersed throughout the compartment by the screen 49 and the top perforated partition part 45. Through this latter partition the air passes into the chamber 56 where it is further diffused and discharged into the lower portion of the compartment A among the product therein through the perforated bottom rack 46, and also through the front and rear end openings 5I, 52.

The remaining portion of the air in the conduit 25 passes up at the rear of the compartment A through the broad flue 26 and enters the chamber 35 in the bottom portion of the compartment B, such entry being through the opening 38.

The air in the chamber 35 is diilused and regulated as to volume by the screen 48 therein and passes from the top screened wall oi' said chamber into the diffusing chamber 38 through the perforated member 34. AThe top wall 31 of the chamber 38, which constitutes the bottom product supporting shelf of the compartment, is perforated more nely than the top wall 34 of the chamber 35, so as to effect an elcient and substantially uniform diiusion of the air throughout the chamber 38 in its discharge into the lower portion of the compartment. The proper balancing of the air distribution to the two compartments A and B is accomplished by the use of the screen 49 in the bottom portion of the compartment A and the screen 4|) in the bottom portion of the compartment B.

The air in the upper portions of the compartments A and B, which is warmed by its passage up past the merchandise in the compartments, is carried rearwardly over the tops of the merchandise and into the upper ends'of the corner down ilues 20 through the screened openings 22 and 23 located in the rear of the respective compartments A and B, as best shown in Figs. 2 and 5. The return air thence passes down the ues 20 and into the rear ends oi the respective return conduits I2 in the base portion of the machine preparatory to again passing through a circulation cycle.

The down flues 20 extend practically to the top of the respective refrigerated zones A and B, and if a zone is well lled with merchandise, much of the returned air is deflected upward and is then pulled over and enters the top of the return air iiues through the expanded mesh guard thereon. However, if the merchandise level is low, much of the returned air is pulled through the lower portion' of the inlet openings to the iues. The topportions of the screened openings 22 and 23 to the refrigerating zones should be lower than the top level of the front walls 9 and 43 of such zones, thus reducing to a minimum the drawing of room air into the refrigerating compartments through the open top. The inlet openings to the return flues also extend downward a distance in each compartment so that if the level of the merchandise in the compartment is low, much if not all of the return air is drawn into the iiues through the lower portions of the return inlets and in greater downwardly spaced relation to the top level of the front walls of the compartment than would be the case if the air was only drawn into the iiues through the extreme top portions of the openings. The provision of these low extending inlet openings for the return iiues tends t lower the level of effective refrigeration in the respective refrigerating zones and to cause less heat pickup from the open top of the zone, thus improving the eiiiciency and economical running of the case.

The present construction of display case lends itself readily to the provision of an extended or continuous display case by placing two or more of the cases end to end. This can be accomplished by merely removing the bracket plates 3| and end plates 8 from the adjacent ends of adjoining cases so that continuous display compartments for the several display zones may be provided.

I wish it understood that my invention is not limited to any specific construction, arrangement or form of the parts, as it is capable of numerous -other at their forward ends, means for creating.

a. forced circulation of air through saidv conduits with the air iiowing in one direction through the intermediate conduit and in the other direction through the side conduits, refrigerating means for the air in its passage through said conduits, and means at the back of the case providing separate communication between the side and intermediate conduits with both said zones to cause a forced circulation of cooled air to each zone from departing i certain of said conduits and a return of warmed f ,air from each zone to certain other of said conduits.

2. In a display case of the class described including a case with separate upper and lower open-top refrigerating zones, an air cooling and circulating system for said zones comprising a series of forwardly and rearwardly extending air conduits in the base of said case below said zones, with said conduits in communication at their forward ends and with at least one forming a cooled air outlet passage and at least one other forming a warm air return inlet passage, means for creating a forced draft in outlet direction through said outlet passage, means in at least oneof said conduits for cooling air passing therethrough, and separate means at the rear of the case for de-n livering cooled air from said outlet passage to each of said zones through its bottom and returning Warm air therefrom to said return conduit, and means in said last means for controlling the distribution of cooled air in predetermined volume to each zone substantially uniformly throughout its bottom.

3. In a display case of the class described including a case with separate upper. and lower open-top refrigerating zones, an air cooling and circulating system for said zones comprising, in the base of the case below the zones, two side air return conduits and an interposed air outlet conduit each extending forwardly and rearwardly of the base and in communication at their forward ends, fan means for creating circulation through said conduits, means for cooling air in its passage through said conduits, and means at the rear of the case for directing a predetermined portion of cooled air from said outlet conduit at its rear end to each of said zones in substantially uniformly distributed relation through its bottom -and for receiving warm air from the upper portion of each `zone and directing it down through the rear corner portions of the case to the rear end of each of said return conduits.

4. In a display case of the class described including a case with separate upper and lower open-top refrigerating zones, an air cooling and circulating system for said zones comprising a series of forwardly and'rearwardly extending air conduits in the base of said case below said zones, with said conduits in communication at their forward ends and with at least one forming a cooled air outlet passage and at least one other forming a warm -air return inlet passage, air distributing amasar means in the bottom of each zone comprising a plurality of chambers and dii'using screens for uniformly distributing air to each zone throughout its bottom, means for creating a forced draft in outlet direction through said outlet passage, means in at least one of said conduits for cooling air passing therethrough. and separate means at the rear of the case for delivering cooled air from said outlet passage to the bottom chambers of each of said zones and to return warm air from the zones to said return conduit.

5. In a display case of the class described including a case with separate upper and lower open-top refrigerating zones, an air cooling and circulating system for said zones comprising, in the base of the case below the zones, two side air return conduits and an interposed air outlet conduit each extending forwardly and rearwardly of the base and in communication at their forward ends, means for creating air circulation through said conduits, means for cooling air in its passage through said conduits, means in the bottom portion of each zone including a, plurality of chambers and air diiusing screens and per.- forated partitions for distributing air substantially equally to a respective zone throughout its bottom from said chambers, and means at the rear of the case for directing a predetermined portion of cooled air from said outlet conduit at its rear end to each of said air distributing means and for returning warm air from the upper por- 8 ing a series of forwardly and rearwardly extending air conduits in the base of the case below said zones, with said conduits in communication at their forward ends and with at least one forming a cooled air outlet passage and at least one other forming a warm air return inlet passage, means for creating a forced draft in outlet direction through said outlet passage, means in at least one of said' conduits for cooling air passing therethrough, and separate means at the rear of the case for delivering cooled air from said outlet passage to each of said zones through its bottom and returning warm air therefrom to said return conduit.

tion of each zone and directing it down through the rear corner portions of the case to the rear end of each said return conduits.

6. In a display case of the class described including a case with separate upper and lower open-top refrigerating zones each having a front wall, an air cooling and circulating system for said zones comprising, in the base of the case below the zones, two side air return conduits and an interposed air outlet conduit each extending forwardly and rearwardly of the case and in communication at their forward ends, means for creating circulation through said conduits, means for cooling air in its passage through said conduits, and means at the rear of the case for directing a predetermined portion of cooled air from said outlet conduit at its rear end to each of said zones through its bottom and for returning warm air from the upper portion of each zone and directing it down through the rear corner portions of the -case to the rear end of each said return conduit, said receiving and return portions of said last means having inlet openings in the respective zones with said openings extending a predetermined distance down into the zone from a point adjacent to but below the top level of the respective front wall ofv the zone.

7. In a display case of the class described including a case with separate superimposed opentop refrigerating zones, a common air cooling and circulating system for said zones compris- 8. In a display case of the class described including a case with separate open-top refrigerating zones disposed one above the other, a common air cooling and circulating system for said zones -comprising at the rear of the zones a series of vertical ducts having comm'unication with the zones, with some of the ducts communicating with the zones through their bottoms, and means in the case below the lower zone for opening communication between the lower ends of said vertical ducts, means for creating a forced air draft through said du-cts, zones and communicating means, and means for cooling the air in its passage through said communicating means.

9. In a display case of the class described including a case with separate open-top refrigerating zones disposed one above the other, a center rear duct for delivering cooled air to the bottom portion of each zone, side rear ducts for receiving warm air from the top portions of the zones and delivering it to the base portion of the case, means in the base portion of the case for directing air from the lower ends of said side ducts to the lower end of said center duct, means for cooling the air passing through said ducts, and means for creating a forced circulation through said means, ducts and zones.

10. In a display case of the class described including a case with separate open-top refrigerating zones disposed one above the other, two vertical iiues disposed side by side at the rear of said zones in communication with different portions of each zone one at the bottom portion and the other at the top portion, means connecting said ducts in the base portion of the case, means for creating a circulation of air through said last means and upward through one and downward through the other of said iiues. and means for cooling the circulating air.

DAVID J. GREILING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Moores Oct. 7, 1947 x 

